One of the advantages to Android's open source nature is that we can poke around in the source code, looking for interesting stuff. This is how we've become aware of some things Google has planned for the stock camera experience. Code from the Android Open Source Project shows that a new camera API has been in development, but it was pulled last month because it wasn't ready for release with KitKat.
According to the AOSP code, Google has been working on building in support for burst shot, improved face detection, and shooting RAW images. Burst shot certainly seems like a no-brainer – almost every other device has that feature. It shouldn't be too hard to implement, either. Face detection has been part of Android for a while, but it seems to get confused by things that look almost like faces a little too often. So again, great. There is also some talk about removable camera elements in the code, but we don't have any indication what that might mean.
Shooting RAW images with the stock camera app would be crazy, and could be what Vic Gundotra was talking about a few months back when he said "insanely great" cameras were coming. A RAW image is not something you usually see on smartphones – it's essentially a file that includes all the data acquired by the image sensor for more powerful editing.
All this cool stuff was in active development (presumably for KitKat) until last month when a commit instructed developers not to merge it with the code base, saying it was "not yet ready." So that's probably why we still have the old camera app and functionality in KitKat. Hopefully this will be sorted out before the next major update.